Heater



FIG. 1 is a perspective view of a heater, in accordance with our design;

FIG. 2 is front view of the heater of FIG. 1;

FIG. 3 is a rear view of the heater of FIG. 1;

FIG. 4 is a left-side view of the heater of FIG. 1;

FIG. 5 is a right-side view of the heater of FIG. 1;

FIG. 6 is a top view of the heater of FIG. 1; and,

FIG. 7 is a bottom view of the heater of FIG. 1.

The broken lines shown in the drawings are for the purpose of illustrating portions of the heater and form no part of the claimed design. 

CLAIM The ornamental design for a heater, as shown and described. 